Online mechanisms for charging electric vehicles in settings with varying marginal electricity costs

We propose new mechanisms that can be used by a demand response aggregator to flexibly shift the charging of electric vehicles (EVs) to times where cheap but intermittent renewable energy is in high supply. Here, it is important to consider the constraints and preferences of EV owners, while eliminating the scope for strategic behaviour. To achieve this, we propose, for the first time, a generic class of incentive mechanisms for settings with both varying marginal electricity costs and multi-dimensional preferences. We show these are dominant strategy incentive compatible, i.e., EV owners are incentivised to report their constraints and preferences truthfully. We also detail a specific instance of this class, show that it achieves ≈ 98% of the optimal in realistic scenarios and demonstrate how it can be adapted to trade off efficiency with profit

Price-based online mechanisms for settings with uncertain future procurement costs and multi-unit demand

We examine the use of online mechanism design in settings where consumers have multi-unit demand, goods are procured and allocated over time, and future procurement costs are uncertain and only become known at the time of allocation. An important application with such characteristics is demand response, where electricity wholesale prices depend on overall demand and the availability of renewables. We formulate this as a mechanism design problem and focus specifically on the property that the mechanism does not revoke any allocated items. In this setting, we characterise a class of price-based mechanisms that guarantee dominant-strategy incentive compatibility, individual rationality, and no cancellation. We present three specific such mechanisms in this domain and evaluate them in an electric vehicle charging setting. By using extensive numerical simulations, we show that a mechanism based on the first-come first-served principle performs well in settings where future procurement costs can be estimated reliably or supply is very tight, while a responsive mechanism performs very well when the estimated procurement costs are highly uncertain and supply is not as tight. We moreover show that a well-defined price-based mechanism can lead to high profits for the operator of the mechanism in many real-world situations

Patient-based assessment with total lesion glycolysis may be associated with therapeutic effects of I-131 meta-iodobenzylguanidine (MIBG) radiotherapy in patients with metastatic neuroendocrine tumors

Background: 131I-labeled meta-iodobenzylguanidine (131I-MIBG) radiotherapy has tumor-progression preventive effects in patients with metastatic neuroendocrine tumors (NECT) such as metastatic pheochromocytoma and paraganglioma. 18F-fluorodeoxyglucose (18F-FDG) PET/CT has been used for therapeutic evaluation after 131I-MIBG radiotherapy on tumor metabolic activity. From a patient management point of view, treatment based on a whole-body parameter is important in evaluating therapeutic effects. Recently, 18F-FDG PET/CT-derived whole-body total metabolic tumor volume (WBMTV) and total lesion glycolysis (WBTLG) have shown prognostic value for various malignant tumors. However, the usefulness of these markers has not been evaluated in terms of the therapeutic effects of 131I-MIBG in patients with metastatic NECT. Therefore, this study aimed to evaluate whether WBMTV and WBTLG were useful to show the therapeutic effects of 131I-MIBG radiotherapy in patients with metastatic NECT.Method: Twenty patients (48.9 ± 14.7 years old, 9 male) with metastatic NECT prospectively had 150 mCi of 131I-MIBG radiotherapy. Based on post-therapeutic 131I-MIBG scintigraphy, patients were divided into 2 groups, namely those with positive 131I-MIBG uptake by metastatic lesions and those with negative uptake. 18F-FDG PET/CT was performed before and 3 months after the first 131I-MIBG radiotherapy. Assessment of 18F-FDG PET/CT-based parameters was performed using dedicated software. Maximum standardized uptake value (SUVmax) was estimated for metastatic lesions. The volume of interest (VOI) placed in the liver was used to determine a threshold value for volume-based analysis as follows: threshold = SUVmean + 3 × standard deviation (SD). WBMTV and WBTLG were calculated accordingly. Results: Among 20 patients, 15 showed positive 131I-MIBG uptake in at least one metastatic lesion. 131I-MIBG uptake was not observed in the remaining 5 patients. There was no significant difference in SUVmax, WBMTV and WBTLG between the two groups before 131I-MIBG therapy. With a lesion-based approach, the difference in %change in SUVmax was not significant between the 131I-MIBG positive and negative groups (-4.1 ± 38.4 % vs. 41.2 ± 168.9 %, P=0.089). With a patient-based approach, there was no significant difference in %change of WBMTV between the 2 groups (20.1 ± 24.3 % vs. 198.0 ± 271.1 %, P=0.060). In contrast, the 131I-MIBG positive group showed significantly lower %change of WBTLG than did the 131I-MIBG negative group (39.3 ± 198.1% vs. 222.5 ± 278.7 %, P = 0.036). Conclusion: In lesion analysis, SUVmax did not indicate significant disease progression in the 131I-MIBG negative group after 131I-MIBG radiotherapy. In contrast, with patient-based analysis, following 131I-MIBG radiotherapy, %change in WBTLG was lower in patients in the 131I-MIBG positive group than in those in the 131I-MIBG negative group, thus indicating the disease progression prevention effects of 131I-MIBG radiotherapy. Therefore, a patient-based approach may more accurately reflect the treatment effects than does a lesion-based approach using SUVmax. Therefore, this parameter may be useful for patient management in metastatic NECT.SNMMI 2019 Annual Meetin

Effectiveness of Short-term Repeated 131I metaiodobenzylguanidine (MIBG) Radiotherapy for Preventing Disease Progression in Patients with Malignant Neuroendocrine Tumors

Background: Single high dose I-131 metaiodobenzylguanidine (MIBG) radiotherapy (12mCi/kg) has revealed slightly better outcome in patients with malignant neuroendocrine tumors (NECT). However, this protocol still shows 35% progressive disease (PD) within 1 year and increases adverse effects. Thus, it requires alternative therapeutic approaches. The aim of this study was to evaluate the effects of relatively short term repeated MIBG therapy for preventing PD in patients with metastatic NECT using computed tomography (CT).Methods: Nineteen patients with metastatic NECT prospectively had repeated 150 mCi of MIBG therapy within 6 months intervals. Total 46 treatments were performed. Patients were subdivided into 2 groups such as positive MIBG scan after the treatment (Group P: N=13) and negative MIBG (Group N, N-6). Mean treatments were 2.7 ±0.5 vs. 1.8 ±0.8times, .Cumulative MIBG dose was 404±72 mCi (7.0 mCi/kg) vs. 275 ± 112 mCi (4.4 mCi/kg) The tumor responses were evaluated by CT with RECIST criteria 6 months after final MIBG therapy and follow-up period from the first MIBG therapy was also observed.Results: The within 1 year PR or SD ratio was significantly higher in Group P (85% vs. 17%, P=0.043). Group P prevented increasing tumor size compared to Group N (% change of total sum longest diameter: -0.8±51.6% vs. 59.5±43.5%, P=0.024). Group P had trend to longer follow-up period compared to Group N (34.8±37.5 vs 15.3±13.7 months, P=0.24). Conclusions: Eighty-five percent metastatic NECT with MIBG positive patients effectively achieved PR or SD disease by relatively short term repeated MIBG therapy. MIBG positive patients were significantly lower within 1 year PD ratio and prevented increasing tumor size than MIBG negative patients using repeated MIBG therapy. Thus, this relatively short period of repeated MIBG treatment may have a potential to be one of therapeutic protocols for metastatic NECT.62nd Society of Nuclear Medicine and Molecular Imagin

A Comparison of Short- and Long-Term Therapeutic Outcomes of Infliximab- versus Tacrolimus-Based Strategies for Steroid-Refractory Ulcerative Colitis

Background/Aims. Antitumor necrosis factor antibodies and calcineurin inhibitors have shown good therapeutic efficacy for steroid-refractory ulcerative colitis (UC). Although some studies have compared the efficacy of infliximab (IFX) and cyclosporin A, there are no published studies comparing IFX and tacrolimus (Tac). This study aimed to compare therapeutic efficacies between IFX- and Tac-based strategies for steroid-refractory UC. Methods. Between July 2009 and August 2013, 95 patients with steroid-refractory UC received either IFX (n=48) or Tac (n=47) in our hospital. In the IFX group, the patients continued to receive maintenance treatment with IFX. In the Tac group, patients discontinued Tac treatment up to 3 months and subsequently received thiopurine. We retrospectively compared the therapeutic outcomes between the groups. Results. There was no significant difference in the colectomy-free rate, clinical remission rate, and clinical response rate at 2 months between the groups. However, relapse-free survival was significantly higher in the IFX group than in the Tac group (p<0.001; log-rank test). The proportions of serious adverse events did not differ between the groups. Conclusion. The findings of our study showed that IFX and Tac have similar short-term therapeutic efficacy for steroid-refractory UC. Maintenance treatment with IFX, however, yields better long-term outcomes than Tac-thiopurine bridging treatment